<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
  <style>
   *{
    margin: 0;
    padding: 0;
   }
   html,body{
    width: 100%;
    height: 100%;
   }
   body{
    background-color: pink;
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: center;
   }
   .heart{
    width: 200px;
    height: 200px;
    background-color: red;
    position: relative;
    transform: rotate(45deg);
    animation: heartbit 1s alternate infinite;
    box-shadow: 0 0 30px red;
   }

   .heart::before{
    content: "";
    width: 200px;
    height: 100px;
    background-color: red;
    position: absolute;
    left: 0;
    top: -99px;
    border-radius: 100px 100px 0 0;
    box-shadow: 0 0 30px red;
   }
.heart::after{
    content: "";
    width: 100px;
    height: 200px;
    background-color: red;
    position: absolute;
    left: -99px;
    top:0px;
    border-radius: 100px 0 0 100px;
    box-shadow: 0 0 30px red;
}
@keyframes heartbit{
    0%{
        transform: rotate(45deg) scale(0.6);
    }
   /* 25%{
        transform: rotate(45deg) scale(0.8);
    }
    50%{
        transform: rotate(45deg) scale(1);
    }
    75%{
        transform: rotate(45deg) scale(1.2);
    }*/
   100%{
        transform: rotate(45deg) scale(1.4);
    }
}
  </style>

</head>
<body>
    <div class="heart"></div>
</body>
</html>